subpanel ground

rtyui2 · 12-06-2007, 08:48 AM

I've installed a subpanel in an addition of my house and have supplied it from the main service panel with a 6-3 wire. Do I also have to run a separate ground (for example, #6 stranded copper) from the subpanel to main panel? Thanks
Mike

J. V. · 12-06-2007, 11:59 AM

All subpanels require a four wire circuit. There is one exception.
2 Hots
1 neutral
1 Ground
6/3 with a bare wire should have everything listed above. The bare wire will be the ground. If you only have three wires total, you are missing one wire. If this is the case you will have to pull the correct cable. This is a feeder and all the conductors are required to be in the same cable or conduit.
If this is in conduit you may be able to add the missing wire. Provided the conduit is of sufficient size.
6/3 NM always has a bare ground wire. is this NM wire?

If you have all four wires you are set. Make sure the grounds and the neutrals are separated. Do not jumper between the grds and neutrals like in the main service panel. If a factory installed jumper is present, remove it.
What size sub panel do you have? Does it have a main breaker? Please respond to these questions as they are important for a safe installation.

Andy in ATL · 12-06-2007, 04:11 PM

You HAVE to have an equipment grounding conductor at your subpanel. This is what you are calling a ground. It has nothing to do with mother Earth...It is actually a "bonding" conductor. It connects all the stuff connected to the subpanel back to the service neutral. It HAS to be seperate from the neutral coming from your main panel. That is why you must have a 4-wire circuit.

Andy

rtyui2 · 12-08-2007, 12:02 AM

Quote:

Originally Posted by J. V.

All subpanels require a four wire circuit. There is one exception.
2 Hots
1 neutral
1 Ground
6/3 with a bare wire should have everything listed above. The bare wire will be the ground. If you only have three wires total, you are missing one wire. If this is the case you will have to pull the correct cable. This is a feeder and all the conductors are required to be in the same cable or conduit.
If this is in conduit you may be able to add the missing wire. Provided the conduit is of sufficient size.
6/3 NM always has a bare ground wire. is this NM wire?

If you have all four wires you are set. Make sure the grounds and the neutrals are separated. Do not jumper between the grds and neutrals like in the main service panel. If a factory installed jumper is present, remove it.
What size sub panel do you have? Does it have a main breaker? Please respond to these questions as they are important for a safe installation.

Sorry for the delay. My sub panel is a 100 amp GE with a main breaker. I've installed 6/3 NM wire from the main service panel to the sub panel. When you say jumper, do you mean the ground and neutral bars are connected by some mechanical means?
thanks
Mike

Andy in ATL · 12-08-2007, 04:43 AM

Quote:

Originally Posted by rtyui2

Sorry for the delay. My sub panel is a 100 amp GE with a main breaker. I've installed 6/3 NM wire from the main service panel to the sub panel. When you say jumper, do you mean the ground and neutral bars are connected by some mechanical means?
thanks
Mike

Exactly. I suspect they are seperate at the factory. Usually you have to add the jumper..

Stubbie · 12-08-2007, 06:17 AM

Mike Ge panels that are the "powermark gold" series that have main breakers are split neutral and both bars are insulated from the panel. A green screw is inserted in the lower part of the bar that the big lug for the service neutral connects to. This is the right side of the panel looking at it on the wall. There is a metal bar or strap that connects the two neutral bars. Ge gives you two options...

1.) You can purchase a ground bar kit and install it on the right hand side of the panel in the mounting holes provided. And you will not install the green screw. So you will have three bars in the panel your two neutral bars and a ground bar. The ground bar will be bonded to the panel metal by the mounting screws.

2.) You can remove the bar between the split neutrals and install the green screw in the left hand bar. The left hand bar now becomes your grounding bar and the right hand becomes your neutral bar.